Prep the pan. Heat the oven to 350°F (175°C). Lightly grease a 12-cup muffin tin with olive oil or use silicone liners. This helps the muffins release cleanly.

Sauté the veggies. Warm 1 tablespoon olive oil in a skillet over medium heat. Add onion and bell pepper; cook 3–4 minutes until slightly soft. Stir in chopped broccoli and cook 2–3 minutes more. You want them crisp-tender, not mushy.

Season the mix. Sprinkle the garlic powder, smoked paprika, salt, and pepper over the veggies. Stir to coat evenly, then remove from the heat. Let cool for a couple of minutes so they don’t scramble the egg whites.

Combine the fillings. In a large bowl, add the cooked turkey, parsley, and cheese if using. Fold in the cooled veggie mixture. This ensures even distribution in every muffin.

Add the egg whites. Pour the egg whites into the bowl and gently mix to combine. The batter will be thin, which is normal.

Fill the cups. Divide the mixture evenly among the muffin cups, filling each about 3/4 full. Give the pan a light tap on the counter to release any air bubbles.

Bake. Place the pan on the center rack and bake 18–22 minutes, until the muffins are set and just barely golden at the edges. A toothpick should come out clean.

Cool and release. Let the muffins cool in the pan for 5 minutes. Run a thin spatula around the edges to lift them out. Cooling helps them firm up and hold their shape.

Serve or store. Enjoy warm, or let them cool completely for meal prep. Add a pinch of salt or a spoon of salsa when serving if you want extra pop.